Supplementary Material for: Pyodermatitis-Pyostomatitis Vegetans with eyelid Involvement: A Rare Manifestation in a Patient with Ulcerative Colitis

Pyodermatitis-pyostomatitis vegetans (PDV-PSV) is a rare and chronic mucocutaneous inflammatory disorder strongly associated with inflammatory bowel disease (IBD), particularly ulcerative colitis (UC). It typically presents with exudative plaques that may affect the face, scalp, and intertriginous areas and also pustular lesions on the oral mucosa. Although several cases with cutaneous and mucosal involvement have been reported, Eyelid involvement remains uncommon and sparsely reported in the literature. We report a 28-year-old male patient recently diagnosed with UC who presented multiple asymptomatic vegetating pustular plaques in the bilateral groin area and multiple pustules on both upper and lower gingiva, lips and hard palate. In a rare manifestation of PDV-PSV, both upper and lower eyelids developed pustules and ulcers, predominantly affecting the left eye. Empirical antimicrobial therapies were initiated under the suspicion of an infectious etiology; however, no clinical improvement was observed. Histopathological evaluation revealed intraepidermal eosinophilic abscess with mild acantholysis and suprabasal clefting, and direct immunofluorescence study was negative supporting the diagnosis of PDV-PSV in the context of UC. The patient was successfully treated with Azathioporine and Adalimumab with significant improvement in gastrointestinal symptoms and mucocutaneous lesions after three months of therapy. This case highlights the importance of considering PDV-PSV in UC patients who developed atypical mucocutaneous manifestations, especially when standard treatment regimen for supposed infectious etiologies fail. Although uncommon, eyelid involvement should be considered as a potential manifestation of PDV-PSV. Histopathological evaluation and direct immunofluorescence study remains essential for diagnosis, especially in cases presenting with unusual manifestations. Consideration of PDV-PSV as a mucocutaneous manifestation of UC is essential to avoid misdiagnoses and prevent unnecessary treatments. While periocular involvement may be rare, the presence of typical skin and oral lesions, along with distinctive histological and immunofluorescence findings, should guide clinicians toward the correct diagnosis.